Portable tank



FIG. 1 is a front perspective view of the portable tank according to this invention showing our new design therefor;

FIG. 2 is a top plan view of the portable tank shown in FIG. 1;

FIG. 3 is a front elevational view of the portable tank shown in FIG. 1;

FIG. 4 is a right side elevational view of the portable tank shown in FIG. 1;

FIG. 5 is a rear elevational view of the portable tank shown in FIG. 1;

FIG. 6 is a left side elevational view of the portable tank shown in FIG. 1; and,

FIG. 7 is a bottom plan view of the portable tank shown in FIG. 1.

The broken line showing of the liquid transfer structures in FIG. 1 is for illustrative environmental purposes only and forms no part of our claimed design. 

The ornamental design for a "portable tank", as shown and described. 